# Question #1b31b

Feb 28, 2016

Consider light as $\textcolor{red}{\text{waves}}$, while discussing its $\textcolor{red}{\text{propagation properties}}$.

And consider light as $\textcolor{m a \ge n t a}{\text{particles}}$ when it interacts in atomic or sub-atomic domains involving its $\textcolor{m a \ge n t a}{\text{emission or absorption}}$.

#### Explanation:

Yes, it is true that light exhibits both wave and particle nature.

Historically, theory about light being waves existed as far back as Aristotle. This was reinforced by thinkers like René Descartes, Robert Hooke, Christiaan Huygens—and later Augustin-Jean Fresnel—mathematically refining the wave viewpoint.
The resulting Huygens–Fresnel principle could explain light's behavior successfully and was subsequently supported experimentally by Thomas Young.
The wave view started dominating since it could explain polarization of light that others could not.

On the other hand an 11 century Arabic scientist Alhazen was the first to explain refraction, reflection, and the operation of a pinhole lens by asserting that light consists of particles. Isaac Newton also developed his corpuscular hypothesis of light.

In 1900 Max Planck made an ad hoc mathematical assumption of quantized energy to explain Black body radiation. Thus we have the famous expression $E = h \nu$. $E$ being energy, $\nu$, the frequency of radiated energy and $h$ is Planck's Constant.
Subsequently in 1905 Albert Einstein extended Planck's black body model to propose his solution to explain the photoelectric effect.

Thus the scientist-world concluded that Electromagnetic radiation propagates following linear wave equations, but can only be emitted or absorbed as discrete particles, thus exhibiting both wave and particle nature simultaneously.